The present invention relates to a printed circuit board tape transferring system, and more specifically, to winding type flexible printed circuit board tape transferring system, which is practical to transfer flexible printed circuit board of different types and widths.
Following fast development of telecommunication industry, semiconductor industry, and planer display industry, different thin-film tapes such as tape carried package, tape ball grid array, and chip on film are intensively used as tapes for printed circuit board. These flexible film tapes commonly have sprocket holes symmetrically arranged along the two opposite lateral sides for positioning in a transferring system. The thickness of these flexible film tapes is about 0.025xcx9c0.125 mm. The width of these flexible film tapes ranges from minimum 35 mm to maximum over 200 mm. When employing these flexible film tapes to the fabrication of flexible printed circuit board, several problems may be encountered as outlined hereinafter.
1. It is difficult to keep the coplanarity of the flexible film tape without any contacts at the region of circuits during the manufacturing process.
2. When transferring the flexible film tape, an improper control of the transmission mechanism may cause the transmission mechanism to damage or deform the sprocket holes of the flexible film tape.
3. A flexible film tape without sprocket holes is not transferable.
4. When running an examination operation, the transferring system must be break off, and then the examination apparatus is operated to examine one segment of the flexible film tape, and then the flexible film tape is carried forwards, and then the examination apparatus is returned to its former position for examining a next segment of the flexible film tape. This repeated transferring and examining procedure wastes much time.
The present invention has been accomplished to provide a winding type flexible printed circuit board tape transferring system, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a winding type flexible printed circuit board tape transferring system, which is practical to transfer flexible printed circuit board tapes of different widths. It is another object of the present invention to provide a winding type flexible printed circuit board tape transferring system, which is practical to transfer flexible printed circuit board tape having sprocket holes as well as flexible printed circuit board tapes without sprocket holes. It is still another object of the present invention to provide a winding type flexible printed circuit board tape transferring system, which keeps the flexible printed circuit board tape flattened transversely extended out when transferring it, preventing the flexible printed circuit board tape from wrinkling. According to one aspect of the present invention, the winding type flexible printed circuit board tape transferring system includes a tape let-off wheel unit controlled to let off a flexible printed circuit board tape for processing, a tape take-up wheel unit controlled to take up the flexible printed circuit board tape from the tape let-off wheel unit, two idle wheel units adapted to guide movement of the flexible printed circuit board tape from the tape let-off wheel unit to the tape take-up wheel unit, a tension control wheel unit adapted to control the tension of the flexible printed circuit board tape being transferred from the tape let-off wheel unit to the tape take-up wheel unit, and at least one work wheel unit adapted to rotate a respective rotary encoder upon movement of the flexible printed circuit board tape, enabling the rotary encoder to output a signal to a control unit indicative of the position of the flexible printed circuit board tape. According to another aspect of the present invention, the wheels of the tension control wheel unit, idle wheel units, and at least one work wheel unit each comprise a wheel axle, a fixed wheel blade fixedly fastened to the wheel axle, an adjustment wheel blade slidably mounted on the wheel axle in parallel to the fixed wheel blade and fixed in the desired position subject to the width of the flexible printed circuit board tape by a holding down screw. The fixed wheel blade and the adjustment wheel blade each have a shoulder adapted to support the flexible printed circuit board tape being transferred from the tape let-off wheel to the take-up wheel.